Eggs which are to be hatched to live poultry are typically candled during embryonic development to identify clear, rotted, and dead eggs (collectively referred to as “non-live eggs”). Non-live eggs are typically removed from incubation to increase available incubator space. In addition, removing non-live eggs can increase hatch rates by as much as 2.0% in old flocks (flock age: 58-62 weeks). This hatch improvement can have a direct value increase of about 0.2 to 0.4¢ per chick in the United States.
In many instances it is desirable to introduce a substance into a live egg prior to hatch. Advances in poultry embryology have made possible the addition of various materials to the embryo or to the environment around the embryo within an avian egg for the purpose of encouraging beneficial effects in the subsequently hatched chick. Such beneficial effects include increased growth, prevention of disease, increasing the percentage hatch of multiple incubated eggs, and otherwise improving physical characteristics of hatched poultry. Additionally, certain types of vaccinations which could previously only be carried out upon either recently hatched or fully mature poultry can now be successful in the embryonated chick. Examples of substances that have been used for, or proposed for, in ovo injection include vaccines, antibiotics and vitamins. In ovo treatment substances and methods of in ovo injection are described, for example, in U.S. Pat. No. 4,458,630 to Sharma et al. and U.S. Pat. No. 5,028,421 to Fredericksen et al.
Unfortunately, it may not be desirable to administer vaccinations into every egg contained within an egg flat. For example, clear eggs are eggs that do not contain an embryo and, thus, may not subsequently hatch as a chick. Clear eggs are conventionally removed prior to in ovo injection because the administration of vaccinations into clear eggs generally serves no purpose and may be considered wasteful. In addition, mold may grow in clear eggs that have been injected, thus increasing the risk of exposing other eggs and hatched chicks to undesirable contamination. Furthermore, injected clear eggs may increase the risk of contamination resulting from albumin leaking therefrom. Dead eggs and rotted eggs are also conventionally removed prior to in ovo injection. Accordingly, it is desirable to quickly identify and remove non-live eggs from an egg flat prior to the in ovo administration of vaccinations via automatic inoculating devices.
In the manufacture of human flu vaccines, seed viruses are inoculated into live eggs and then three days later virus material is harvested in batches of eggs. Dead or rotted eggs can contaminate batches of virus harvested from live eggs so that reliable removal of detected non-live eggs is important to minimize contamination and bioburden in harvests. Removal system malfunctions are likely since eggs have holes where they were inoculated and egg goo pulled from the punch hole tends to plug vacuum lines of removal apparatus. In this application small numbers of eggs are typically removed, perhaps 2% to 5%, and human access to harvesting operations for some types of flu vaccines are highly restricted so that a reliable removal is valuable for both economic and health reasons.
It may also be desirable to selectively remove other types of eggs from an egg flat. For example, it may be desirable to remove all male eggs, all female eggs, etc. As another example, it may be desirable to remove all live eggs in order to move them to another egg flat or injection apparatus.
Conventional egg handling devices remove eggs from egg flats by pulling the eggs with a vacuum cup of a suction device. The vacuum cup generally lifts the eggs vertically from a flat and carries them to a disposal location. A conventional device 10 for removing eggs 12 from an egg flat 14 is illustrated in FIG. 1. A plurality of “egg pickers” 16 are configured to engage the upwardly facing portions of a respective plurality of individual eggs 12 within the flat 14, and hold the eggs by suction while carrying them to a receptacle 18.
Sometimes eggs to be removed from a flat cannot be removed by an egg removal device. For example, an egg may be tightly wedged in the pocket of a flat. In addition, spilled egg contents and other foreign matter may act as an adhesive that binds an egg within a pocket of a flat. Conventional suction devices may fail to remove an egg from a flat for other reasons, as well. For example, the vacuum cup of a suction device may fail to seat adequately on an egg, or vacuum leaks may occur because of a feather or other debris on the egg shell, or because of a crack in the egg shell. In addition, a suction device may not be able to remove an egg when there is insufficient vacuum, which may have various causes, such as a torn vacuum cup, clogged venturi or vacuum line, etc. Unfortunately, conventional egg removal systems do not have a way of detecting when an egg that should be removed from a flat is not removed.